1. Fields of the Invention
The present invention relates to a padlock, and more particularly, to a padlock with replaceable shackle and cylinder. The padlock has non-conductive feature so as to be used with electrical equipment to ensure safety of the maintainers.
2. Descriptions of Related Art
The conventional padlocks are widely used locks and some of them have replaceable shackle and cylinder so that theses padlocks can be used with different types of equipment or objects without purchasing whole new locks to save the cost. By replaceable shackles and cylinder, the unauthorized persons difficult to guess the correct key. Alternatively, the cylinders of multiple locks can be set to have the same structure so that the users do not need to carry different keys.
In order to keep the maintainers safety when maintaining electrical equipment, many countries have set as a law to require a lock is necessary for the electric equipment such as the power boxes so as to prevent unauthorized access and operation. Because the electric equipment have potential risk of electric shocking which can seriously injure the maintainers when opening or locking the power boxes, so that the locks used to the electric equipment have to be non-conductive.
U.S. Pat. No. 5,755,121 discloses a lock body having opposing identical molded plastic sections which are composed of a first part and a second part. Each of the first and second pars has an inside, an outside and an upright wall that is attached to the inside and ends at the two sides of the inside. The first and second parts are connected to each other by connecting integral pins to holes. The first and second parts may also be connected to each other by way of ultra-sonic welding. A room is defined between the first and second parts when the sides of the first and second parts are connected to each other. However, the connection by the pins and holes is easily damaged because the lock is made by plastic material. If the connection is made by way of ultra-sonic welding, then the lock cannot be dis-assembled, so that it is impossible to replace the cylinder or shackle, and this does not meet the requirements in the market. If the lock should be replaced, then a whole new lock has to be purchased and this increases the cost.
The present invention intends to provide a padlock to eliminate the shortcomings mentioned above.